mac80211: minstrel: make prob_ewma u16 instead of u32

Saves about 1.2 KiB memory per station
Signed-off-by: NFelix Fietkau <nbd@nbd.name>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

net/mac80211/rc80211_minstrel.h

@@ -59,7 +59,7 @@ struct minstrel_rate_stats {
 	/* statistis of packet delivery probability
 	 *  prob_ewma - exponential weighted moving average of prob
 	 *  prob_ewmsd - exp. weighted moving standard deviation of prob */
-	unsigned int prob_ewma;
+	u16 prob_ewma;
 	u16 prob_ewmv;
 
 	/* maximum retry counts */